FIG. 5.

OmpA⁺ E. coli-infected macrophages are protected from cytochrome c release into the cytoplasm from mitochondria induced by ST. Both THP-M and RAW 264.7 cells grown in 100-mm dishes were either untreated (control) or treated with ST for 3 h after infection with OmpA⁺ and OmpA⁻ E. coli for 1 h as described in Materials and Methods. The mitochondrial and cytosolic fractions were prepared, and the proteins (30 μg) were separated by SDS-10% polyacrylamide gel electrophoresis. The cytosolic proteins were subjected to immunoblotting with anti-cytochrome c antibody (dilution, 1:1,000). The same blot was stripped and reprobed with anti-β-actin antibody (dilution, 1:1,000) to determine the equality of loading. The mitochondrial fractions were subjected to immunoblotting with anti-Bcl_XL, anti-Bax, and anti-cytochrome c antibodies.